1/*
2 * Copyright (C) 2014 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.android.printspooler.widget;
18
19import android.content.Context;
20import android.graphics.drawable.BitmapDrawable;
21import android.graphics.drawable.Drawable;
22import android.print.PrintAttributes.MediaSize;
23import android.print.PrintAttributes.Margins;
24import android.util.AttributeSet;
25import android.view.View;
26import com.android.printspooler.model.PageContentRepository;
27import com.android.printspooler.model.PageContentRepository.RenderSpec;
28import com.android.printspooler.model.PageContentRepository.PageContentProvider;
29
30/**
31 * This class represents a page in the print preview list. The width of the page
32 * is determined by stretching it to take maximal horizontal space while the height
33 * is computed from the width using the page aspect ratio. Note that different media
34 * sizes have different aspect ratios.
35 */
36public class PageContentView extends View
37        implements PageContentRepository.OnPageContentAvailableCallback {
38
39    private PageContentProvider mProvider;
40
41    private MediaSize mMediaSize;
42
43    private Margins mMinMargins;
44
45    private Drawable mEmptyState;
46
47    private boolean mContentRequested;
48
49    public PageContentView(Context context, AttributeSet attrs) {
50        super(context, attrs);
51    }
52
53    @Override
54    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
55        mContentRequested = false;
56        requestPageContentIfNeeded();
57    }
58
59    @Override
60    public void onPageContentAvailable(BitmapDrawable content) {
61        setBackground(content);
62    }
63
64    public PageContentProvider getPageContentProvider() {
65        return mProvider;
66    }
67
68    public void init(PageContentProvider provider, Drawable emptyState,
69            MediaSize mediaSize, Margins minMargins) {
70        final boolean providerChanged = (mProvider == null)
71                ? provider != null : !mProvider.equals(provider);
72        final boolean loadingDrawableChanged = (mEmptyState == null)
73                ? emptyState != null : !mEmptyState.equals(emptyState);
74        final boolean mediaSizeChanged = (mMediaSize == null)
75                ? mediaSize != null : !mMediaSize.equals(mediaSize);
76        final boolean marginsChanged = (mMinMargins == null)
77                ? minMargins != null : !mMinMargins.equals(minMargins);
78
79        if (!providerChanged && !mediaSizeChanged
80                && !marginsChanged && !loadingDrawableChanged) {
81            return;
82        }
83
84        mProvider = provider;
85        mMediaSize = mediaSize;
86        mMinMargins = minMargins;
87
88        mEmptyState = emptyState;
89        mContentRequested = false;
90
91        // If there is no provider we want immediately to switch to
92        // the empty state, so pages with no content appear blank.
93        if (mProvider == null && getBackground() != mEmptyState) {
94            setBackground(mEmptyState);
95        }
96
97        requestPageContentIfNeeded();
98    }
99
100    private void requestPageContentIfNeeded() {
101        if (getWidth() > 0 && getHeight() > 0 && !mContentRequested
102                && mProvider != null) {
103            mContentRequested = true;
104            mProvider.getPageContent(new RenderSpec(getWidth(), getHeight(),
105                    mMediaSize, mMinMargins), this);
106        }
107    }
108}
109